Affiner votre recherche
Résultats 1-10 de 39
Modulation of Fc receptors for IgG on bovine polymorphonuclear neutrophils by interferon-gamma through de novo RNA transcription and protein synthesis.
1994
Worku M. | Paape M.J. | Marquardt W.W.
Polymorphonuclear neutrophils (PMN) from 4 cows were preincubated (30 minutes, 37 C) in either actinomycin D (100 micrograms/ml) or puromycin (10 micrograms/ml), inhibitors of mRNA transcription and protein translation, or in medium 199. The PMN were incubated for a further 4.5 hours in medium containing 100 U of recombinant bovine interferon-gamma (rboIfn-gamma). The PMN were then incubated with bovine IgG1, IgG2, IgM, or aggregated IgG (aIgG; 4 C, 12 hours) for flow cytometric analysis, using fluoresceinated isotype-specific antibody. The percentage of PMN binding the ligand and the logarithmic mean fluorescent channel (LMFC), an indicator of the amount of receptor (R) expression, were recorded. Competitive inhibition of ligand binding was measured by incubating PMN with fluoresceinated IgG2 in the presence or absence of 100-fold excess of IgG1, IgG2, and aIgG. Activation with rboIfn-gamma induced a 4.5-fold increase in binding of IgG1 and a fivefold increase in LMFC for IgG2. These increases were inhibited by actinomycin D and puromycin. Percentage of PMN binding aIgG decreased after activation by rboIfn-gamma. Interferon-gamma treatment did not affect binding or LMFC of IgM. However, binding of IgM was reduced by treatment with actinomycin D. Binding of fluoresceinated IgG2 was inhibited by unlabeled IgG1, IgG2, and aIgG. Results indicate that bovine PMN Fc receptors (FcR) for IgG1 and IgG2 were rboIfn-gamma inducible, that induction required de novo transcription and translation, that a heterogeneous population of FcR exist on bovine PMN, and that IgG1 and IgG2 share a common FcR. Further, bovine PMN are capable of gene activation and are responsive to changes in their environment, thus being amenable to modulation for effective pathogen destruction.
Afficher plus [+] Moins [-]Proteins specified by bovine herpesvirus-2.
1988
Adams S.W. | Balachandran N. | Hutt Fletcher L.M.
Characterization of polypeptides synthesized and secreted by oviductal epithelial cell explants obtained from young, fertile and aged, subfertile mares.
1996
Brinsko S.P. | Ignotz G.G. | Ball B.A. | Thomas P.G.A. | Currie W.B. | Ellington J.E.
Clinicopathological analysis of expression of enhancer of zeste homologue 2 in canine mammary carcinoma
2022
Ren, Xiaoli | Fan, Yuying | Li, Yongqi | Shi, Dongmei | Liu, Yun
Enhancer of zeste homologue 2 (EZH2) is the human homologue of Drosophila zeste gene enhancer. The aim of this study was to determine the expression of EZH2 in canine mammary carcinomas (CMCs) and its relationship with clinicopathological features. The expression of EZH2 mRNA and protein in 53 CMC tissue and 8 normal mammary gland tissue samples was measured by quantitative real-time PCR and immunohistochemical staining assay, respectively. The relationship between EZH2 protein expression and clinicopathological features was analysed by χ2 test to further explore the clinical significance of EZH2 in CMCs. Compared with normal mammary gland tissues, EZH2 mRNA expressions were significantly increased in CMC tissues (P < 0.01). Moreover, normal mammary glands did not express the EZH2 protein but carcinomic glands did, and expression increased in CMCs with high histological grades, especially in histological grade II (P < 0.05). However, EZH2 expression was not related to age, tumour size, or metastasis (P > 0.05). The expression of EZH2 in one type of CMC was not significantly different from the expression in any other type (P > 0.05). EZH2 is highly expressed in CMCs, indicating that it can be used as a molecular marker for early diagnosis, prognosis, or therapy of CMCs.
Afficher plus [+] Moins [-]Expression of vascular cell adhesion molecule 1 (VCAM-1) in the mammary lymph nodes of cows with subclinical mastitis
2017
Chen, Yuanyuan | Yang, Wei | Xu, Chuang
Introduction: Vascular cell adhesion molecule 1 (VCAM-1) is a member of Ig superfamily. The aim of this study was to prepare highly specific polyclonal antibodies against bovine VCAM-1 and to evaluate the expression of VCAM-1 in the mammary lymph nodes of cows with subclinical mastitis.Material and Methods: The VCAM-1 gene was cloned from bovine Peyer’s patches and inserted into the pGEX-4T-1 and pET-28a vectors. The recombinant plasmids pGEX-4T-1/VCAM-1 and pET-28a/VCAM-1 were transferred into Escherichia coli BL21 and the recombinant strains were induced by isopropyl-D-thiogalactoside to produce fusion proteins tagged with polyhistidine (His) and glutathione S-transferase (GST), respectively. The expressed fusion proteins His-VCAM-1 and GST-VCAM-1 were identified by SDS-PAGE and Western blot. His-VCAM-1 protein was used as an antigen to immunise Wistar rats and polyclonal antibody serum against VCAM-1 was obtained.Results: The serum titre tested by indirect ELISA was 128,000 using GST-VCAM-1 as the well coating antigen. Western blots indicated that the antibody recognised recombinant VCAM-1 protein as well as endogenous VCAM-1. In addition, using qPCR and Western blot, VCAM-1 mRNA and protein expression levels were measured in dairy cows with subclinical mastitis. It was demonstrated that VCAM-1 levels in the mammary lymph nodes of the cows were significantly higher than those from healthy controls (P < 0.05).Conclusion: These results are to our knowledge the first report that VCAM-1 expression in the mammary lymph nodes is elevated in dairy cows with subclinical mastitis.
Afficher plus [+] Moins [-]Identification of novel pathways in pathogenesis of ketosis in dairy cows via iTRAQ/MS
2016
Shu, Shi | Xu, Chuchu | Xia, Cheng | Xiao, Xinhuan | Wang, Gang | Fan, Ziling | Cao, Yu | Wang, Yanhui | Zhang, Hongyou
Introduction: To identify novel pathways involved in the pathogenesis of ketosis, an isobaric tag for relative and absolute quantitation/mass spectrometry was used to define differences in protein expression profiles between healthy dairy cows and those with clinical or subclinical ketosis.Material and Methods: To define the novel pathways of ketosis in cattle, the differences in protein expression were analysed by bioinformatics. Go Ontology and Pathway analysis were carried out for enrich the role and pathway of the different expression proteins between healthy dairy cows and those with clinical or subclinical ketosis.Results: Differences were identified in 19 proteins, 16 of which were relatively up-regulated while the remaining 3 were relatively down-regulated. Sorbitol dehydrogenase (SORD) and glyceraldehyde-3-phosphate dehydrogenase (G3PD) were up-regulated in cattle with ketosis. SORD and G3PD promoted glycolysis. These mechanisms lead to pyruvic acid production increase and ketone body accumulation.Conclusion: The novel pathways of glycolysis provided new evidence for the research of ketosis.
Afficher plus [+] Moins [-]Analysis of β-agonists in different biological matrices by liquid chromatography–tandem mass spectrometry
2021
Śniegocki, Tomasz | Sell, Bartosz | Posyniak, Andrzej
Wide use is made of β-agonists in therapy due to their smooth muscle–relaxant properties. They also have a side effect of increasing muscle mass. Besides improving oxygen utilisation as bronchodilators, β-agonists increase protein synthesis and promote fat burning. The growth- and performance-enhancing effects are often exploited in illegal use. The guiding objective of this study was to develop a procedure for the determination of β-agonists by a single method in different types of matrices. Five grams of homogenised samples were subjected to enzymatic hydrolysis with β-glucuronidase in ammonium acetate, pH 5.2. Purification was performed by solid phase extraction. Analytes were eluted with 10% acetic acid in methanol. The eluted β-agonists were analysed by high-performance liquid chromatography–tandem mass spectrometry. Validation results met the requirement of the confirmation criteria according to European Commission Decision 2002/657/EC in terms of apparent recoveries (93.2–112.0%), repeatability (3.1–7.1%) and intra-laboratory reproducibility (4.1–8.2%). The method can be successfully applied in the detection and determination of clenbuterol, salbutamol, mabuterol, mapenterol, terbutaline, brombuterol, zilpaterol, isoxsuprine and ractopamine in feed, drinking water, urine, muscle, lung and liver matrices.
Afficher plus [+] Moins [-]2-DE-MS based proteomic investigation of dairy cows with footrot
2016
Introduction: The differentially expressed proteins between healthy cows and those with footrot were identified to explore changes in protein profiles associated with the disease. Material and Methods: Out of 36 cows selected for the experiment, 18 footrot-affected cows were included in the treatment group (group T) and 18 unaffected cows were included in the control group (group C). Plasma samples from groups T and C were subjected to two-dimensional electrophoresis analysis and differentially expressed proteins were identified by matrix-assisted laser desorption/ionisation tandem time-of-flight mass spectrometry. Bioinformatics, including gene ontology analysis and pathway analysis, was used for analysing all proteins. Results: Out of 63 spots identified by 2DE, 33 were selected for mass spectrum analysis, which identified 11 differentially expressed proteins in 26 spots. Footrot led to changes in profiles in plasma proteins that were classified to the pathway of inflammatory response, complement, and blood coagulation, among others. Conclusion: This study provides evidence of the defence mechanisms of cows with footrot to explore strategies for treatment.
Afficher plus [+] Moins [-]Mitochondrial theory of skeletal muscle ageing –new facts, new doubts
2019
Słodki, Sebastian | Bogucka, Joanna
For many years, scientists have been pursuing research on skeletal muscle ageing both in humans and animals. Studies on animal models have extended our knowledge of this mechanism in humans. Most researchers agree that the major processes of muscle ageing occur in the mitochondria as the major energy production centres in muscle cells. It is believed that decisive changes occur at the enzymatic activity level as well as in protein synthesis and turnover ability. Deregulation of ion channels and oxidative stress also play significant roles. In particular, in recent years the free radical theory of ageing has undergone considerable modification; researchers are increasingly highlighting the partly positive effects of free radicals on processes occurring in cells. In addition, the influence of diet and physical activity on the rate of muscle cell ageing is widely debated as well as the possibility of delaying it through appropriate physical exercise and diet programmes. Numerous studies, especially those related to genetic processes, are still being conducted, and in the near future the findings could provide valuable information on muscle ageing. The results of ongoing research could answer the perennial question of whether and how we can influence the rate of ageing both in animals and humans.
Afficher plus [+] Moins [-]Influence of hydrogen-rich saline on hepatocyte autophagy during laparoscopic liver ischaemia-reperfusion combined resection injury in miniature pigs
2018
Bai, Ge | Li, Hui | Ge, Yansong | Zhang, Qianzhen | Zhang, Jiantao | Chen, Mingzi | Liu, Tao | Wang, Hongbin
The purpose of this study was to investigate the protective effect of hydrogen-rich saline (HRS) against liver ischaemia-reperfusion combined resection injury. Eighteen miniature pigs were randomly divided into three groups: a sham operated group (sham group, laparoscopic liver ischaemia-reperfusion combined resection injury group (IRI group), and a hydrogen-rich saline intervention group (IRI + HRS group). Samples of hepatic tissue and serum were collected at the time of reperfusion and then 3 h, 1 d, and 3 d post reperfusion. Liver function, oxidative stress, autophagy-related mRNA genes, and protein expression were evaluated. Changes in cell and tissue ultrastructure were examined by transmission electron microscopy. Compared with the sham group, the level of autophagy of hepatocytes increased in the IRI and IRI + HRS groups, corresponding to high oxidative stress and severe liver function injury. Liver function, antioxidant content, autophagy levels, and liver injury were improved after intervention with HRS in the IRI + HRS group compared with the IRI group. Intervention with hydrogen-rich saline could exert a protective effect against liver ischaemia-reperfusion combined resection injury through the reduction of oxidative stress and hepatocyte autophagy.
Afficher plus [+] Moins [-]